There are Major Flaws in 538's Do-It-Yourself Election Model


538 has an interactive map in which you can play around with scenarios to see how the odds change. It is flawed.

Video Instruction

The video uses Florida in a very flawed manner.

You can Explore The Ways Trump Or Biden Could Win The Election

Do It Yourself

Let's change one state, Florida. 

Change in Florida


  • A change in Florida dramatically changes the forecast elsewhere, flipping Arizona and North Carolina as well.
  • Arizona went from 67-33 Biden to 74-24 Trump.
  • North Carolina went from 67-33 Biden to 69-31 Trump.

The inherent problem is 538 made no distinction between Trump winning by 0.5% or Trump winning by 2.5%. 

To the interactive model, a win is a win. 

Moreover, the model appears to assume that we know the result in Florida, but have nothing but 538's projections for the other states. 

Arizona may very well be decided on election night. We will know something about North Carolina as well.

Changing Florida and Arizona

Two States Decided Florida and Arizona

In the above example, I set Florida and Arizona, one for Trump and one for Biden. That's not an unlikely possibility, in any direction. 

Now the results are back to 83-16 in favor of Biden.

Early Vote Counting

Early Vote Counting

Third Problem

The video example makes it appear as if this all comes down to Florida again. It doesn't. 

So no, we cannot say that if Trump wins Florida, he has a 40% chance of winning. 

  1. The margin of Trump's alleged Florida win certainly matters. 538's interactive model says a win is a win.
  2. We will not magically see Florida in a vacuum.
  3. The video example over-emphasizes Florida. It is not that simple.

In practice, we will have partial results elsewhere and perhaps even full results in Arizona. 

The interactive model seriously needs work. I suggest it be reworked to put in custom percentages instead of projecting winners.


Comments (13)
No. 1-5

The 538 model uses demographic data to adjust the odds of winning other states based on the demos of states where you manually select the winner. That’s why a single-state change in a swing state like Florida can dramatically affect the overall race.


Rarely comment - if ever, or "long time listener, 1st time caller' - MISH keep up the good work - read you for more than a decade - appreciate what you do.

From an outside point of view - Canuck from the great white north - I will be so glad when this US election is over. Americans are the best neighbours we could hope for, but oh my, your elections are a mess and tough to watch. I know you could have better candidates and do so much better......just saying.

Anyhow, I wouldn't want an outsider commenting on our elections wrt to whom we should vote for, so I certainly won't do that. I have no horse in this race. However if it makes anyone feel any better, here is a quick link to mock our present clown or 'Mr Socks':

I'm sure some of you need a little laugh at this point. Hope it helps and you all get to vote and keep safe.

Dodge Demon
Dodge Demon

I think Denninger had a shot of scotch for every “C’mon, man” the other day.


Nate is very sensitive to his failure in 2016. Something tells me this convoluted visualization is meant to cover his back when his predictions go awry.

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